JP2004038153A - Nip forming device for developing device, and developing device - Google Patents

Nip forming device for developing device, and developing device Download PDF

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Publication number
JP2004038153A
JP2004038153A JP2003133257A JP2003133257A JP2004038153A JP 2004038153 A JP2004038153 A JP 2004038153A JP 2003133257 A JP2003133257 A JP 2003133257A JP 2003133257 A JP2003133257 A JP 2003133257A JP 2004038153 A JP2004038153 A JP 2004038153A
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Prior art keywords
developing
nip forming
nip
developing device
elastic layer
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JP2003133257A
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Japanese (ja)
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Chinju Kim
金　鎮受
Se-Hyun Lyu
ユウ　セヒョン
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Samsung Electronics Co Ltd
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Samsung Electronics Co Ltd
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
    • G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
    • G03G15/0806—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer on a donor element, e.g. belt, roller
    • G03G15/0813—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer on a donor element, e.g. belt, roller characterised by means in the developing zone having an interaction with the image carrying member, e.g. distance holders

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Dry Development In Electrophotography (AREA)
  • Color Electrophotography (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize an image quality and to prevent damage of a photosensitive body by lessening a contact impact and forming a fixed development nip between a developer carrier and a photosensitive body when bringing the developer carrier into contact with the photosensitive drum to perform development. <P>SOLUTION: A nip forming device for a developing device includes nip forming members 100a and 100b which are arranged in both ends of one of a developer carrier 113 and a photosensitive body 111 so as to be placed between the photosensitive body and the developer carrier, and at least a part of a peripheral surface of each nip forming member is formed so as to project from the peripheral surface of the developer carrier or the photosensitive body having the nip forming member arranged thereon, to such an extent that a prescribed development nip t may be formed at the time of contact between the developer carrier and the photosensitive body. Nip forming members are constituted of cylinder bodies and elastic layers formed on outer peripheral surfaces of the cylinder bodies. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は，現像装置のニップ形成装置及び現像装置にかかり，さらに詳しくは電子写真方式で画像形成を行う複写機，プリンター，ファクシミリなどのような画像形成装置の現像装置うち，接触現像方式で現像を行う現像装置のニップ形成装置及び現像装置に関する。
【０００２】
【従来の技術】
従来の，接触現像方式で現像を行う複写機，プリンター，ファクシミリなどのような電子写真方式画像形成装置には，例えば，図１に示すようなカラー画像形成装置がある。
【０００３】
このカラー画像形成装置１０は，感光体駆動源（図示せず）により一方向に連続回転されるドラム状の感光体１１を備える。感光体１１の外周近傍には，第１帯電器１２と，レーザースキャニングユニット（Ｌａｓｅｒ　ＳｃａｎｎｉｎｇＵｎｉｔ：以下，ＬＳＵと称する）２０と，イエロー，マゼンタ，シアン及びブラックの現像剤をそれぞれ収容して接触現像方式で感光体１１に供給する，四つの現像剤搬送体としての現像装置３１，３２，３３，３４と，転写搬送部６０と，除電ランプ８７と，クリーニング除電部８０とが感光体１１の回転方向に沿って所定の位置に配置される。
【０００４】
第１帯電器１２は，スコロトロン帯電器であって，感光体１１を均一に帯電する役割を果たす。ＬＳＵ２０は，レーザー光源などによって感光体１１を軸方向にライン状に露光する。
【０００５】
それぞれの現像装置３１，３２，３３，３４は，現像ローラ１３，現像剤収容部１６，現像剤供給ローラ１５，及び現像剤規制部材５１を備える。現像ローラ１３，現像剤供給ローラ１５，及び現像剤規制部材５１は，現像装置駆動源（図示せず）によりそれぞれ回転駆動され，現像剤収容部１６の現像剤は，現像剤供給ローラ１５を介して現像ローラ１３に供給される。現像ローラ１３に供給された現像剤は，現像剤規制部材５１によりその厚さが規制されて，現像ローラ１３上に現像剤の薄層が形成される。
【０００６】
それぞれの現像装置３１，３２，３３，３４は，現像装置案内部材（図示せず）内を往復動できるように支持されており，それぞれ回転軸５６に固定されたカム３５，３６，３７，３８によって感光体１１側に解除スプリング７４に抗して移動可能に設けられる。回転軸５６の回転は電磁クラッチ（図示せず）によって規制される。
【０００７】
また，現像剤を用いて静電潜像を可視化する際には，現像ローラ１３には現像バイアス電圧が印加される。ここで，ネガティブ−ポジティブ反転された可視画像を形成する場合は，現像バイアス電圧は，現像ローラ１３の表面に形成された現像剤の薄層の帯電極性が感光体１１の帯電極性と同一極性になるように印加される。
【０００８】
転写搬送部６０は，現像装置３１，３２，３３，３４により感光体１１に形成されたカラー画像を静電的に記録紙Ｐに転写する。クリーニング除電部８０は，転写後に感光体１１に残留した現像剤を除去する。
【０００９】
このように構成される従来の画像形成装置１０による画像形成過程を以下に説明する。先ず，印刷命令が下されると，感光体１１は感光体駆動源（図示せず）により連続して回転し，これにより感光体１１の表面は第１帯電器１２により均一に帯電される。
【００１０】
帯電された領域が最初に形成される色の現像装置，例えばイエロー現像装置３１，の現像位置ｄに到達すると，イエロー現像装置３１の電磁クラッチが通電され，これによりイエロー現像装置３１は偏心カム３５により感光体１１の方向に移動して現像位置にセットされる。
【００１１】
そして，感光体１１の表面にはＬＳＵ２０により光源が照射されて，イエロー静電潜像が形成される。前記形成されたイエロー静電潜像は，現像位置ｄで画像の先端部から後端部に至るまで連続してイエローの可視画像に現像される。イエロー可視画像の現像が完了し，画像の後端部がイエローの現像位置ｄを通過すると，偏心カム３５は回転し，これによりイエロー現像装置３１は感光体１１から分離されて待機位置にセットされる。
【００１２】
次に，画像の先端部が２番目に形成される色の現像装置，例えばマゼンタ現像装置３２，の現像位置ｅに到達すると，マゼンタ現像装置３２の電磁クラッチが通電され，これによりマゼンタ現像装置３２は偏心カム３６により感光体１１の方向に移動して現像位置にセットされる。
【００１３】
同時に，感光体１１上に形成されたイエロー可視画像は，非動作状態の転写搬送部６０，除電ランプ８７及びクリーナ除電部８０を通過して，再び第１帯電器１２の下方に位置するようになる。このとき，形成済の可視画像が通過する転写搬送部６０及びクリーナ除電部８０は，可視画像が曇らないよう，動作時以外は感光体１１と接触しない状態に位置する。
【００１４】
イエロー可視画像が形成された感光体１１は，第１帯電器１２の下方位置で再度第１帯電器１２により均一に帯電される。そして，ＬＳＵ２０により光源を照射されてマゼンタ静電潜像がイエロー可視画像の上に重ねて形成される。前記マゼンダ静電潜像は，マゼンタの現像位置ｅでマゼンダ可視画像に現像される。マゼンタの可視画像の形成が完了し，画像の後端部がマゼンタの現像位置ｅを通過すると，偏心カム３６は回転し，これによりマゼンタ現像装置３２は感光体１１から分離されて待機位置にセットされる。
【００１５】
次に，画像の先端部が３番目に形成される色の現像装置，例えばシアン現像装置３３の現像位置ｆに到達すると，シアン現像装置３３の電磁クラッチが通電され，これによりシアン現像装置３３は偏心カム３７により感光体１１の方向に移動して現像位置にセットされる。
【００１６】
このとき，イエローとマゼンタの合成可視画像は，転写搬送部６０，除電ランプ８７，及びクリーナ除電部８０を通過し，再び第１帯電器１２の下方に位置するようになる。そして，感光体１１は第１帯電器１２により再び均一に帯電され，前記形成されたイエローとマゼンタの合成可視画像が形成された感光体１１は，ＬＳＵ２０により光源を照射されてシアン静電潜像がマゼンダ可視画像の上に重ねて形成される。前記シアンの静電潜像は，シアンの現像位置ｆでシアン可視画像に現像される。シアンの可視画像の形成が完了し，画像の後端部がシアンの現像位置ｆを通過すると，偏心カム３７は回転し，シアン現像装置３３は感光体１１から分離されて待機位置にセットされる。
【００１７】
次いで，黒色の画像を同様の方法でシアン可視画像の上に重ねて形成し，全カラーの画像形成が完了する。
【００１８】
転写搬送部６０は，このようにして感光体１１上に形成されたカラー画像を，記録紙供給部により同期をとって搬送されてくる記録紙Ｐに転写する。記録紙Ｐに転写された画像は記録紙定着部に搬送され，記録紙定着部によって定着されて画像の形成が完了する。そして，画像が形成された記録紙Ｐは，画像形成装置１０の外部に排出される。
【００１９】
一方で，記録紙Ｐへの転写が完了した感光体１１は，除電ランプ８７によって除電され，感光体１１の表面に残留している現像剤は，クリーナ除電部８０の回転ブラシ８１によって除去される。このようにして，感光体１１は初期の状態に復帰される。
【００２０】
このように従来の画像形成装置１０は，４色の現像装置３１，３２，３３，３４の現像ローラ１３が順次感光体１１の表面に接触して現像剤を感光体１１に付着させて現像を行うので，合計４回の現像が行なわれる。このとき，それぞれの現像装置３１，３２，３３，３４の現像ローラ１３は，偏心カム３５，３６，３７，３８により，感光体１１と一定圧力で接触する現像位置，または感光体１１から離脱される待機位置にセットされる。
【００２１】
一方，非接触現像方式で現像を行う複写機，プリンター，ファクシミリなどのような電子写真方式画像形成装置には，例えば特許文献１に示すような画像形成装置がある。この画像形成装置の非接触方式現像装置は，感光体と一定の距離をおいて対向して設けられる現像スリーブを備え，前記現像スリーブには，前記感光体と現像スリーブを一定の距離に保つために突出部材が設けられる。
【００２２】
【特許文献１】
特開平１２−０８１７８５号公報
【００２３】
【発明が解決しようとする課題】
しかし，前述した従来の接触現像方式の現像装置を備える画像形成装置１０においては，現像ローラ１３が感光体１１に接触する際の衝撃により画像の品質が不安定になるという問題があった。
【００２４】
詳しく説明すると，感光体１１は一般的に感光層などが外周面に被覆されるアルミニウムのような高硬度の円筒部材で構成されており，また現像ローラ１３もアルミニウムまたは樹脂のような高硬度の円筒部材で構成される。従って，現像装置３１，３２，３３，３４の現像ローラ１３が感光体１１に接触して現像を行なう際に発生する接触衝撃は感光体１１に直接伝達されて，感光体１１に現像される画像の品質が不安定になる。
【００２５】
また，現像装置３１，３２，３３，３４が偏心カム３５，３６，３７，３８により感光体１１と接触したり離隔される際に発生する圧力変動による衝撃は，感光体１１が現像過程以外の過程，例えば帯電過程または露光過程，を経ている際にも感光体１１に直接伝達されて画像の品質に影響を及ぼしたり，また，感光体１１の感光層に機械的ストレスを与えて感光体１１の寿命を短縮するという問題点があった。
【００２６】
そこで，本発明は，このような問題に鑑みてなされたもので，その目的とするところは，現像剤搬送体が感光ドラムに接触して現像を行う際に生じる接触衝撃を緩和させることにより，画像の品質を安定させ，感光体の損傷を防止することができる現像装置のニップ形成装置及び現像装置を提供することにある。
【００２７】
更に，本発明の他の目的は，現像剤搬送体が感光ドラムに接触して現像を行う際に，現像剤搬送体と感光体との間に一定の現像ニップが形成されるよう維持することにより画像の品質を安定させることができる現像装置のニップ形成装置及び現像装置を提供するところにある。
【００２８】
【課題を解決するための手段】
上記課題を解決するために，本発明のある観点によれば，静電潜像が形成される感光体と，前記感光体に接触して前記静電潜像に現像剤を付着させて可視画像を形成する少なくとも一つ以上の現像剤搬送体とを備える電子写真方式画像形成装置の現像装置のニップ形成装置であって，前記現像剤搬送体または前記感光体のいずれか一方の両端に，前記感光体と前記現像剤搬送体との間に位置するように配置されるニップ形成部材を含み，前記各ニップ形成部材の円周面の少なくとも一部は，前記ニップ形成部材が配置される前記現像剤搬送体または前記感光体の円周面よりも，前記現像剤搬送体と前記感光体とが接触したときに所定の現像ニップが形成される程突出されて形成されること，を特徴とする現像装置のニップ形成装置が提供される。
【００２９】
このような本発明にかかる現像装置のニップ形成装置によれば，現像剤搬送体の両端に前記現像剤搬送体の円周面よりも突出して形成されるニップ形成部材が設けられるか，または，感光体の両端に前記感光体の円周面よりも突出して形成されるニップ形成部材が設けられる。そして，いずれの場合も，静電潜像が形成された感光体に現像剤搬送体を接触させて現像を行う際には，前記ニップ形成部材の突出して形成された部分が先ず前記現像剤搬送体または前記感光体に接触する。これにより，前記現像剤搬送体と前記感光体とは，前記突出形成された部分の厚さと等しい厚さの現像ニップを互いの間に形成しながら接触することができる。また，前記ニップ形成部材の突出形成された部分は緩衝材の役割りも果たし，前記現像剤搬送体と前記感光体とが接触する際の衝撃を緩和して，画像の品質を安定させ，かつ感光体の損傷を防止することができる。
【００３０】
ここで，前記ニップ形成部材は，円筒体及び前記円筒体の外部表面に形成された非導電性の弾性層を有する，前記現像剤搬送体の両端に一つずつ設置される二つの小ローラにより構成されるようにすれば，前記現像剤搬送体の両端に設けられるニップ形成部材の弾性層が前記現像剤搬送体と前記感光体とが接触する際に緩衝材の役割りを果たし，衝撃を緩和させることができる。
【００３１】
このとき，前記ニップ形成部材の円筒体は，前記現像剤搬送体と同一外径を有する前記現像剤搬送体に装着される別個の部品として形成され，前記ニップ形成部材の弾性層は，前記円筒体の外部表面に円周方向に形成された弾性層支持溝に射出成形により形成されるように構成することが望ましい。
【００３２】
また，前記ニップ形成部材の円筒体は，前記現像剤搬送体と同一外径を有する前記現像剤搬送体に装着される別個の部品として形成され，前記ニップ形成部材の弾性層は，前記円筒体の外部表面に円周方向に形成された弾性層支持溝に挟込まれる別個の部品として形成されるように構成することもできる。
【００３３】
更に，前記ニップ形成部材の円筒体は，前記現像剤搬送体と同一外径を有して前記現像剤搬送体と一体に形成され，前記ニップ形成部材の弾性層は，前記円筒体の外部表面に円周方向に形成された弾性層支持溝に射出成形により形成されるように構成することもできる。
【００３４】
そして更に，前記ニップ形成部材の円筒体は，前記現像剤搬送体と同一外径を有して前記現像剤搬送体と一体に形成され，前記ニップ形成部材の弾性層は，前記円筒体の外部表面に円周方向に形成された弾性層支持溝に挟込まれる別個の部品として形成されるように構成することもできる。
【００３５】
このとき，前記ニップ形成部材による衝撃緩衝の度合い，及び前記ニップ形成部材により形成される現像ニップの厚さは，前記円筒体の外部表面から突出された前記弾性層の厚さによって調節することができる。
【００３６】
また，前記ニップ形成部材による衝撃緩衝の度合い，及び前記ニップ形成部材により形成される現像ニップの厚さは，前記円筒体の外部表面から突出された前記弾性層の硬度によって調節することもできる。
【００３７】
上記課題を解決するために，本発明の別の観点によれば，静電潜像が形成される第１胴体と，前記第１胴体との間に所定の現像ニップを形成して前記第１胴体と接触して前記静電潜像を現像する第２胴体と，前記第２胴体から前記第１胴体へ加えられる接触衝撃を吸収して前記第１胴体と前記第２胴体とを接触させる衝撃緩衝部材とを含むこと，を特徴とする現像装置が提供される。
【００３８】
このような本発明にかかる現像装置によれば，現像装置の第１胴体に形成された静電潜像に第２胴体を接触させて前記静電潜像を現像する際に，衝撃緩衝部材が前記第１胴体と第２胴体との接触衝撃を吸収して緩和するので，接触衝撃による現像品質の劣化を防止して画像の品質を安定させ，かつ接触衝撃による感光体の損傷を防止することができる。
【００３９】
このとき，前記第２胴体は一つの直径を有し，前記衝撃緩衝部材は一つの直径を有し，前記現像ニップの厚さは，前記第２胴体の直径と前記衝撃緩衝部材の直径との差と同一である如く構成すれば，前記衝撃緩衝部材は，前記現像装置の第１胴体に形成された静電潜像に前記第２胴体を接触させて現像する際に，前記第１胴体と第２胴体との接触衝撃を吸収して緩和する役割りを果たすと同時に，前記第１胴体と第２胴体との間に現像ニップを形成する役割も果たすことができる。
【００４０】
また，前記第２胴体は一つのシャフトを有するローラであり，前記衝撃緩衝部材は前記シャフト上に配置された円筒体を含む如く構成すれば，前記衝撃緩衝部材の円筒体は前記第２胴体と同一軸上で前記第２胴体と共に回転可能となる。
【００４１】
また，前記第２胴体は一つのシャフトを有するローラであり，前記ローラの両端部には更に複数のシャフトが配置され，前記衝撃緩衝部材は前記複数のシャフトのそれぞれに配置された複数の円筒体を含むように構成することもできる。このように構成すれば，前記衝撃緩衝部材の複数の円筒体は，前記第２胴体の回転に伴なって前記第２胴体のシャフトを中心とする円周上を回転移動することができる。従って，前記衝撃緩衝部材は，前記第２胴体の回転に伴なって回転移動する前記複数の円筒体によって，前記第１胴体と第２胴体との接触衝撃を吸収する役割りを果たすことができる。
【００４２】
また，前記衝撃緩衝部材の円筒体は，非導電性の材質から成る如く構成すれば，前記衝撃緩衝部材の円筒体が前記第１胴体に接触した際に前記第１胴体の表面の現像剤が前記円筒体に付着するのを防止することができる。また，前記衝撃緩衝部材の円筒体は，プラスチックで形成されることが望ましい。
【００４３】
更に，前記衝撃緩衝部材は，前記円筒体の外部表面に形成された非導電性の弾性層をさらに含む如く構成すれば，前記弾性層が前記第１胴体と第２胴体との接触衝撃を吸収する役割りを果たす。また，前記弾性層は非導電性の材質から成るため，前記第１胴体の表面に付着している現像剤が静電気により付着するのを防止することができる。
【００４４】
このとき，前記衝撃緩衝部材の円筒体の直径は，前記第２胴体の直径と同一であることが望ましい。また，前記現像ニップの厚さは，前記衝撃緩衝部材の弾性層の厚さ，及び／または弾性層の硬度を変化させることにより調節することができる。
【００４５】
上記課題を解決するために，本発明の別の観点によれば，静電潜像が形成される第１回転体と，前記第１回転体との間に所定の現像ニップを形成して前記第１回転体と共に回転して前記静電潜像を現像する第２回転体と，前記第２回転体と同軸上で共に回転する円筒体，及び前記第１回転体と接触するよう前記円筒体の外周面に形成されてその硬度と厚さのうち少なくとも一つによって前記現像ニップの厚さを決定する弾性層を備える，ニップ形成部材とを含むこと，を特徴とする現像装置が提供される。
【００４６】
このような本発明にかかる現像装置によれば，前記現像装置の第１回転体に形成された静電潜像に第２回転体を接触させて前記静電潜像を現像する際の現像ニップの厚さは，ニップ形成部材の弾性層の硬度と厚さのうち少なくとも一つによって決定されるので，前記弾性層の硬度及び／または厚さを調整することによって前記現像ニップの厚さを調整することができる。
【００４７】
上記課題を解決するために，本発明の別の観点によれば，静電潜像が形成される複数の第１胴体と，前記複数の第１胴体とそれぞれ対応して設けられ，対応する前記第１胴体との間に所定の現像ニップを形成して前記第１胴体とそれぞれ接触して，それぞれ異る色相の現像剤で前記静電潜像を現像する複数の第２胴体と，前記それぞれの第２胴体から前記対応する第１胴体へ加えられる接触衝撃を吸収して前記それぞれの第１胴体と第２胴体とを接触させる複数の衝撃緩衝部材とを含むこと，を特徴とする現像装置が提供される。
【００４８】
このような本発明にかかる現像装置によれば，前記現像装置は，現像剤のカラー数に相当する数の第１胴体，第２胴体，及び衝撃緩衝部材をそれぞれ備える。そして，対応して設けられる一組の第１胴体，第２胴体，及び衝撃緩衝部材においては，第１胴体に形成された静電潜像に第２胴体を接触させて前記静電潜像を現像する際に，衝撃緩衝部材が第１胴体と第２胴体との接触衝撃を吸収して緩和するので，接触衝撃による現像品質の劣化を防止して画像の品質を安定させ，かつ接触衝撃による感光体の損傷を防止することができる。
【００４９】
【発明の実施の形態】
以下に添付図面を参照しながら，本発明にかかる現像装置のニップ形成装置及び現像装置の好適な実施の形態について詳細に説明する。なお，本明細書及び図面において，実質的に同一の機能構成を有する構成要素については，同一の符号を付することにより重複説明を省略する。
【００５０】
本発明の実施の形態にかかる現像装置のニップ形成装置１００の概略構成を図２に示す。本実施形態にかかる現像装置のニップ形成装置１００はカラー画像形成装置に設けられる。前記カラー画像形成装置は，図２にその一部分が示される感光体１１１と現像装置１３１とを備える。
【００５１】
感光体１１１は円筒ドラム状の形状を有し，その表面にはその電位特性を利用して静電潜像が形成される。現像装置１３１は，感光体１１１と互いに接触して回転しつつ感光体１１１に形成された前記静電潜像に現像剤を付着して可視画像を形成する，現像剤搬送体としての役割りを果たす現像ローラ１１３を備える。前記カラー画像形成装置には，このような現像装置１３１が４つ設けられ（一つだけ図示），接触現像方式でカラー画像の印刷を行う。
【００５２】
感光体１１１は，シャフト１１２ｃを有するアルミニウムパイプまたはシリンダ１１２と，シリンダ１１２の両側縁部の非感光層部１１２ｂを除いた外部表面に一定の厚さでコーティングされる感光層１１２ａとにより構成される。
【００５３】
現像装置１３１の現像ローラ１１３は，シャフト１１３ａを有し，アルミニウム材質などからなる金属，または導電性プラスチック材質からなる円筒形の管またはシリンダで構成される。
【００５４】
現像装置１３１の現像ローラ１１３以外の部分の構成は，図１に示した従来のカラー画像形成装置１０の現像装置３１，３２，３３，３４の構成と同一であるため，ここでは詳細な説明を省く。
【００５５】
現像ローラ１１３のシャフト１１３ａの両端には，本実施形態にかかる現像装置のニップ形成装置１００が形成される。ニップ形成装置１００は，現像ローラ１１３が該当カラーの現像を行うために感光体１１１の方向に移動して感光体１１１と接触する際の接触衝撃を緩和する。同時に，現像装置のニップ形成装置１００は，現像ローラ１１３と感光体１１１との間に所定の厚さの現像ニップを形成しつつ現像ローラ１１３及び感光体１１１が回転するようにすることにより，安定した現像品質を維持する。
【００５６】
ニップ形成装置１００は，それぞれ現像ローラ１１３の両端に設けられ，その外径が現像ローラ１１３の円周面から前述した所定の現像ニップの厚さほど突出される外径を有する，ニップ形成部材１００ａ，１００ｂにより構成される。ニップ形成部材１００ａ，１００ｂは，現像ローラ１１３と感光体１１１との間に所定の厚さの現像ニップを形成すると同時に，現像ローラ１１３が感光体１１１に接触する際の接触衝撃を緩和する衝撃緩衝部材としての役割りも兼ねる。
【００５７】
図３は，本実施形態にかかる現像装置のニップ形成装置１１０のニップ形成部材１００ａの構成を示す図である。図３の右側半分はニップ形成部材１００ａの平面図であり，左側半分は横断面図である。また，図４は，図３のニップ形成部材１００ａのＩ−Ｉ線断面図，即ち縦断面図である。
【００５８】
ニップ形成部材１００ａ，１００ｂは，現像ローラ１１３のシャフト１１３ａの両端に一つずつ配置される，円筒体１１０及び弾性層１２０により構成される二つの小ローラである。円筒体１１０は，ポリカボネート（ＰＣ）やポリアセタル（ＰＯＭ）などのような非導電性のプラスチック材から成る。弾性層１２０は，円筒体１１０の外部表面に形成され，非導電性のゴムなどの材質から成る。
【００５９】
ニップ形成部材１００ａ，１００ｂの双方の円筒体１１０は，それぞれ現像ローラ１１３と同一の外径を有し，現像ローラ１１３のシャフト１１３ａに強制嵌合される。
【００６０】
また，円筒体１１０の外部表面１１６には，円周方向に弾性層１２０を形成できるように，弾性層支持溝１３０が形成される。弾性層１２０は弾性層支持溝１３０内に射出成形により形成されることが望ましい。また，別個の部品として弾性層１２０を形成してから，円筒体１１０の弾性層支持溝１３０に挟み込むこともできる。
【００６１】
円筒体１１０は，現像ローラ１１３または現像ローラ１１３のシャフト１１３ａと一体に形成することもできる。この場合，円筒体１１０を現像ローラ１１３とは別個の部品として形成する場合と同様に，円筒体（図示せず）の外径は現像ローラ１１３と同一の外径であり，また，円筒体の外部表面には弾性層（図示せず）を形成するための弾性層支持溝（図示せず）が形成される。同様に，弾性層は，弾性層支持溝内に射出成形により形成されるか，または別個の部品として形成されて弾性層支持溝内に挟み込まれる。
【００６２】
弾性層支持溝１３０内に形成される弾性層１２０の，円筒体１１０の外部表面１１６から突出される部分，即ち厚さｔを有する突出部分は，ローラ１１３が感光体１１１の方向に移動して感光体１１１と接触する際の接触衝撃を緩和し，また，現像品質を均一かつ安定的に維持する現像ニップを形成する。その効果は，弾性層１２０が，射出成形または別個の部品としてのいずれの方法で形成されても同様である。
【００６３】
このとき，前記突出部分の厚さｔを調節することにより，前記現像ニップが，現像品質が最も良好となる最適な値となるように調節することができる。同様に，前記突出部分の厚さｔを調節することにより，感光体１１１と現像ローラ１１３とが接触する際の接触衝撃の緩衝の度合いを調節することができる。このように，現像ニップの厚さ，及び衝撃緩衝の度合いは，弾性層１２０の厚さにより調節することができるが，弾性層１２０の硬度により調節することもできる。
【００６４】
また，弾性層１２０及び／または円筒体１１０は，感光体１１１の感光層１１２ａと接触するため，静電気により現像剤が付着する可能性があるが，非導電性の材質から成るためにこれを防止することができる。従って，ニップ形成装置１００の汚れによって画像欠陥などの画像品質劣化現象が発生するのを防止することができる。
【００６５】
このように，本実施形態にかかる現像装置のニップ形成装置１００は，弾性層１２０により，現像ローラ１１３が感光体１１１に接触する際の接触衝撃を緩和しながら一定の圧力で感光体１１１と接触することによって，所定の厚さｔの現像ニップを維持して画像の品質を良好にし，また接触衝撃による画像品質の劣化及び感光体１１１の感光層１１２ａの損傷を防止することができる。このとき，感光体１１１と現像ローラ１１３の両方，特に感光体１１１が，プラスチックまたは金属などの硬い材質で構成されれば，現像装置のニップ形成装置１００はより優れた効果を奏することができる。
【００６６】
次に，このような構成の現像装置のニップ形成装置を備える本実施形態にかかる現像装置について説明する。ニップ形成装置１００を備える現像装置１３１は，現像ローラ１１３の他に，図１に示す従来の現像装置１３と同様に，現像剤収容部１６，現像剤供給ローラ１５，及び現像剤規制部材５１を備える。
【００６７】
従来の技術と同様，感光体１１１には静電潜像が形成され，また，該当するカラーの現像装置１３１は前記静電潜像を現像するために，感光体１１１の方向に移動して現像位置にセットされる。そして，現像ローラ１１３，現像剤供給ローラ１５，及び現像剤規制部材５１は，現像装置駆動源によりそれぞれ回転駆動され，現像剤収容部１６の現像剤は現像剤供給ローラ１５を介して現像ローラ１１３に供給される。現像ローラ１１３に供給された現像剤は，現像剤規制部材５１によりその厚さが規制されて，現像ローラ１１３上に現像剤の薄層が形成される。
【００６８】
そして，現像ローラ１１３が感光体１１１に接触させて現像を行う際には，本実施形態にかかる現像装置１３１は，現像装置のニップ形成装置１００によって，接触衝撃が緩衝され，また，感光体１１１と現像ローラ１１３との間に適切な現像ニップが形成される。
【００６９】
このように構成される本実施形態にかかる現像装置を備える画像形成装置の画像形成過程は，従来の技術と同様なため，その説明は省略する。
【００７０】
以上，添付図面を参照しながら本発明に係る好適な実施形態について説明したが，本発明は係る例に限定されないことは言うまでもない。当業者であれば，特許請求の範囲に記載された範疇内において，各種の変更例または修正例に想到し得ることは明らかであり，それらについても当然に本発明の技術的範囲に属するものと了解される。
【００７１】
例えば，本実施形態にかかる現像装置のニップ形成装置１００は，現像ローラ１１３のシャフト１１３ａの両端に設けられるが，ニップ形成装置１００を同様な構成で感光体１１１の両端に設けるようにすることもできる。
【００７２】
また，本実施形態にかかる現像装置のニップ形成装置１００のニップ形成部材１００ａ，１００ｂは，現像ローラ１１３の両端にそれぞれ現像ローラのシャフト１１３ａと同軸上に一つずつ配置される円筒体であるが，このように現像ローラ１１３の端部に一つの円筒体を設ける代わりに，現像ローラ１１３の端部に更に複数のシャフトを設けて，前記複数のシャフトのそれぞれに複数の円筒体を配置して，現像装置のニップ形成装置を構成することもできる。このように構成すれば，前記複数の円筒体は，現像ローラ１１３の回転に伴なって現像ローラのシャフト１１３ａを中心とする円周上を回転移動することができる。従って，現像装置のニップ形成装置は，現像ローラ１１３の回転に伴なって回転移動する前記複数の円筒体によって，感光体１１１と現像ローラ１１３との接触衝撃を吸収することができる。
【００７３】
また，本実施形態にかかる現像装置のニップ形成装置１００のニップ形成部材１００ａ，１００ｂは，現像ローラ１１３が感光体１１１に接触する際の衝撃を緩和する衝撃緩衝部材も兼ねるが，衝撃緩衝部材をニップ形成部材とは別に形成して設けてもよい。
【００７４】
また，本実施形態にかかる現像装置のニップ形成装置を備える現像装置は，前述した一つの感光体１１１を備えてその表面に異なるカラーの画像が重ねて現像される構成の代わりに，現像剤のカラー数に相当する数の複数の感光体を備えて，前記それぞれの感光体には一つのカラーの画像が現像される構成を有することもできる。
【００７５】
【発明の効果】
以上詳述したように本発明によれば，現像剤搬送体が感光体に接触して現像を行う際に，緩衝材となる弾性層を有するニップ形成部材を設けることにより，現像剤搬送体が感光体に接触する際の接触衝撃を緩和して，接触衝撃による画像品質の劣化及び感光体の感光層の損傷を防止することができる現像装置のニップ形成装置及び現像装置を提供できるものである。このとき，感光体と現像剤搬送体の両方，特に感光体が，プラスチックまたは金属などの硬い材質で構成されれば，より優れた接触衝撃緩衝効果を奏することができる。
【００７６】
更に，本発明によれば，前記ニップ形成部材を設けることにより，現像剤搬送体と感光体との接触衝撃を緩和すると同時に，現像剤搬送体と感光体とが一定の圧力で接触して所定の厚さの現像ニップが形成されて，画像の品質を良好に維持することができる現像装置のニップ形成装置及び現像装置を提供できるものである。
【図面の簡単な説明】
【図１】従来のカラー画像形成装置の概略構成を示す図である。
【図２】本発明の実施の形態にかかる現像装置のニップ形成装置の概略構成を示す平面図である。
【図３】同実施の形態にかかる現像装置のニップ形成装置のニップ形成部材の構成を示す図である。
【図４】図３のＩ−Ｉ線断面図である。
【符号の説明】
１０　画像形成装置
１１　感光体
１２　第１帯電器
１３　現像ローラ
１５　現像剤供給ローラ
１６　現像剤収容部
２０　レーザースキャニングユニット
３１，３２，３３，３４　　現像装置
３５，３６，３７，３８　カム
５１　現像剤規制部材
５６　回転軸
６０　転写搬送部
７４　解除スプリング
８７　除電ランプ
８０　クリーニング除電部
１１１　感光体
１１２ａ　感光層
１１３　現像ローラ
１１３ａ　シャフト
１３１　現像装置
１００ａ，１００ｂ　ニップ形成部材
１１０　円筒体
１２０　弾性層
１３０　弾性層支持溝[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a nip forming device and a developing device of a developing device, and more specifically, to a developing device of a contact developing method among developing devices of an image forming device such as a copying machine, a printer, a facsimile, etc. for forming an image by an electrophotographic method. The present invention relates to a nip forming device and a developing device of a developing device for performing the following.
[0002]
[Prior art]
2. Description of the Related Art A conventional electrophotographic image forming apparatus such as a copier, a printer, a facsimile or the like which performs development by a contact developing method includes, for example, a color image forming apparatus as shown in FIG.
[0003]
The color image forming apparatus 10 includes a drum-shaped photoconductor 11 that is continuously rotated in one direction by a photoconductor drive source (not shown). A first charger 12, a laser scanning unit (hereinafter, referred to as LSU) 20, and yellow, magenta, cyan and black developers are accommodated in the vicinity of the outer periphery of the photoconductor 11, respectively, and a contact developing method is provided. The developing devices 31, 32, 33, and 34 as four developer conveyance bodies, the transfer conveyance section 60, the charge elimination lamp 87, and the cleaning charge elimination section 80, which are supplied to the photoconductor 11, rotate in the rotation direction of the photoconductor 11 Is arranged at a predetermined position.
[0004]
The first charger 12 is a scorotron charger and plays a role of uniformly charging the photoconductor 11. The LSU 20 linearly exposes the photoconductor 11 in the axial direction using a laser light source or the like.
[0005]
Each of the developing devices 31, 32, 33, and 34 includes a developing roller 13, a developer container 16, a developer supply roller 15, and a developer regulating member 51. The developing roller 13, the developer supply roller 15, and the developer regulating member 51 are each rotationally driven by a developing device drive source (not shown), and the developer in the developer accommodating portion 16 is supplied via the developer supply roller 15. And supplied to the developing roller 13. The thickness of the developer supplied to the developing roller 13 is regulated by the developer regulating member 51, and a thin layer of the developer is formed on the developing roller 13.
[0006]
Each of the developing devices 31, 32, 33, and 34 is supported so as to be able to reciprocate in a developing device guide member (not shown), and cams 35, 36, 37, and 38 fixed to a rotating shaft 56, respectively. Accordingly, it is movably provided on the photoconductor 11 side against the release spring 74. The rotation of the rotating shaft 56 is regulated by an electromagnetic clutch (not shown).
[0007]
When a developer is used to visualize an electrostatic latent image, a developing bias voltage is applied to the developing roller 13. Here, when a negative-positive inverted visible image is formed, the developing bias voltage is set so that the charging polarity of the thin layer of the developer formed on the surface of the developing roller 13 is the same as the charging polarity of the photoconductor 11. Is applied.
[0008]
The transfer conveyance section 60 electrostatically transfers the color image formed on the photoconductor 11 by the developing devices 31, 32, 33, and 34 to the recording paper P. The cleaning charge removing unit 80 removes the developer remaining on the photoconductor 11 after the transfer.
[0009]
An image forming process by the conventional image forming apparatus 10 configured as described above will be described below. First, when a print command is issued, the photoconductor 11 is continuously rotated by a photoconductor drive source (not shown), whereby the surface of the photoconductor 11 is uniformly charged by the first charger 12.
[0010]
When the charged area reaches the developing position d of the developing device of the color to be formed first, for example, the yellow developing device 31, the electromagnetic clutch of the yellow developing device 31 is energized. And is set in the developing position by moving in the direction of the photoconductor 11.
[0011]
Then, a light source is irradiated on the surface of the photoconductor 11 by the LSU 20 to form a yellow electrostatic latent image. The formed yellow electrostatic latent image is developed into a yellow visible image continuously from the leading end to the trailing end of the image at the developing position d. When the development of the yellow visible image is completed and the rear end of the image passes the yellow development position d, the eccentric cam 35 rotates, whereby the yellow developing device 31 is separated from the photoconductor 11 and set to the standby position. You.
[0012]
Next, when the leading end of the image reaches the developing position e of the developing device of the second color, for example, the magenta developing device 32, the electromagnetic clutch of the magenta developing device 32 is energized, whereby the magenta developing device 32 is turned on. Is moved in the direction of the photoconductor 11 by the eccentric cam 36 and set at the developing position.
[0013]
At the same time, the yellow-visible image formed on the photoreceptor 11 passes through the non-operating transfer / conveyance unit 60, the static elimination lamp 87 and the cleaner static elimination unit 80, and is again positioned below the first charger 12. Become. At this time, the transfer / transport unit 60 and the cleaner neutralizing unit 80 through which the formed visible image passes are positioned so as not to contact the photoconductor 11 except during operation so that the visible image is not fogged.
[0014]
The photoconductor 11 on which the yellow visible image is formed is uniformly charged again by the first charger 12 at a position below the first charger 12. Then, the light source is irradiated by the LSU 20, and a magenta electrostatic latent image is formed so as to overlap the yellow visible image. The magenta electrostatic latent image is developed into a magenta visible image at a magenta development position e. When the formation of the visible image of magenta is completed and the rear end of the image passes the developing position e of magenta, the eccentric cam 36 rotates, whereby the magenta developing device 32 is separated from the photoconductor 11 and set to the standby position. Is done.
[0015]
Next, when the leading end of the image reaches the developing position f of the developing device for the third color, for example, the cyan developing device 33, the electromagnetic clutch of the cyan developing device 33 is energized. The eccentric cam 37 moves in the direction of the photoconductor 11 and is set at the developing position.
[0016]
At this time, the combined visible image of yellow and magenta passes through the transfer / conveyance unit 60, the static elimination lamp 87, and the cleaner static elimination unit 80, and is again positioned below the first charger 12. The photoreceptor 11 is uniformly charged again by the first charger 12 and the formed photoreceptor 11 on which the combined visible image of yellow and magenta is formed is irradiated with a light source by the LSU 20 to form a cyan electrostatic latent image. Are formed over the magenta visible image. The cyan electrostatic latent image is developed into a cyan visible image at a cyan development position f. When the formation of the cyan visible image is completed and the rear end of the image passes the cyan developing position f, the eccentric cam 37 rotates, and the cyan developing device 33 is separated from the photoconductor 11 and set to the standby position. .
[0017]
Next, a black image is formed over the cyan visible image by the same method, and the image formation of all colors is completed.
[0018]
The transfer conveyance section 60 transfers the color image formed on the photoreceptor 11 in this way to the recording paper P conveyed synchronously by the recording paper supply section. The image transferred to the recording paper P is conveyed to a recording paper fixing unit, and is fixed by the recording paper fixing unit, thereby completing the image formation. Then, the recording paper P on which the image has been formed is discharged outside the image forming apparatus 10.
[0019]
On the other hand, the photoreceptor 11 having completed the transfer to the recording paper P is discharged by the discharging lamp 87, and the developer remaining on the surface of the photoreceptor 11 is removed by the rotating brush 81 of the cleaner discharging unit 80. . Thus, the photoconductor 11 is returned to the initial state.
[0020]
As described above, in the conventional image forming apparatus 10, the developing rollers 13 of the developing devices 31, 32, 33, and 34 of the four colors sequentially contact the surface of the photoconductor 11 to cause the developer to adhere to the photoconductor 11, thereby performing the development. Therefore, a total of four developments are performed. At this time, the developing rollers 13 of the respective developing devices 31, 32, 33, 34 are separated from the photoconductor 11 by the eccentric cams 35, 36, 37, 38 at a developing position where the photoconductor 11 is brought into contact with the photoconductor 11 at a constant pressure. Is set to the standby position.
[0021]
On the other hand, as an electrophotographic image forming apparatus such as a copier, a printer, a facsimile, etc., which performs development by a non-contact developing method, there is, for example, an image forming apparatus as disclosed in Japanese Patent Application Laid-Open No. H11-163873. The non-contact type developing device of the image forming apparatus includes a developing sleeve provided to face the photoconductor at a predetermined distance, and the developing sleeve includes a developing sleeve for keeping the photoconductor and the developing sleeve at a predetermined distance. Is provided with a protruding member.
[0022]
[Patent Document 1]
JP-A-12-08785
[0023]
[Problems to be solved by the invention]
However, in the image forming apparatus 10 including the above-described conventional contact developing type developing device, there is a problem that the quality of an image becomes unstable due to an impact when the developing roller 13 contacts the photoconductor 11.
[0024]
More specifically, the photoconductor 11 is generally formed of a high-hardness cylindrical member such as aluminum having a photosensitive layer or the like coated on the outer peripheral surface, and the developing roller 13 is also formed of a high-hardness cylinder such as aluminum or resin. It is composed of a cylindrical member. Therefore, the contact impact generated when the developing roller 13 of the developing devices 31, 32, 33, and 34 comes into contact with the photoconductor 11 to perform development is directly transmitted to the photoconductor 11, and the image developed on the photoconductor 11 is formed. The quality of the product becomes unstable.
[0025]
Further, an impact due to a pressure fluctuation generated when the developing devices 31, 32, 33, and 34 come into contact with or are separated from the photoconductor 11 by the eccentric cams 35, 36, 37, and 38 is caused when the photoconductor 11 is not subjected to the developing process. During a charging process or an exposing process, for example, the light is directly transmitted to the photoconductor 11 to affect the quality of the image. There is a problem of shortening the life of the device.
[0026]
Accordingly, the present invention has been made in view of such a problem, and an object of the present invention is to reduce a contact impact generated when a developer carrier comes into contact with a photosensitive drum to perform development. An object of the present invention is to provide a nip forming device and a developing device of a developing device that can stabilize image quality and prevent damage to a photoconductor.
[0027]
Still another object of the present invention is to maintain a constant developing nip between the developer transport body and the photoconductor when the developer transport body contacts the photosensitive drum to perform development. Accordingly, an object of the present invention is to provide a nip forming device and a developing device of a developing device capable of stabilizing the quality of an image.
[0028]
[Means for Solving the Problems]
According to one aspect of the present invention, there is provided a photoconductor on which an electrostatic latent image is formed, and a method of contacting the photoconductor with a developer and adhering a developer to the electrostatic latent image to form a visible image. A nip forming device of a developing device of an electrophotographic image forming apparatus, comprising: at least one developer conveying member that forms A nip forming member disposed so as to be located between the photosensitive member and the developer conveying member, wherein at least a part of a circumferential surface of each of the nip forming members is the developing device on which the nip forming member is disposed; The developer carrier and the photoconductor are formed so as to protrude beyond a circumferential surface of the photoconductor so that a predetermined developing nip is formed when the developer carrier and the photoconductor come into contact with each other. A nip forming device for a developing device is provided. .
[0029]
According to such a nip forming device of the developing device according to the present invention, the nip forming members that are formed so as to protrude from the circumferential surface of the developer conveying body are provided at both ends of the developer conveying body, or Nip-forming members are provided at both ends of the photoconductor so as to protrude from the circumferential surface of the photoconductor. In any case, when the developer is brought into contact with the photoreceptor on which the electrostatic latent image has been formed, the projecting portion of the nip forming member firstly contacts the developer transporter. Contacts the body or the photoreceptor. Thus, the developer carrier and the photoconductor can be in contact with each other while forming a developing nip having a thickness equal to the thickness of the protruding portion therebetween. Further, the protruding portion of the nip forming member also serves as a cushioning material, and alleviates an impact when the developer conveyance body and the photoconductor come into contact with each other, stabilizes image quality, and Damage to the photoconductor can be prevented.
[0030]
Here, the nip forming member is formed by two small rollers, one at each end of the developer carrier, having a cylindrical body and a non-conductive elastic layer formed on the outer surface of the cylindrical body. According to this structure, the elastic layers of the nip forming members provided at both ends of the developer transporting body play a role of a cushioning material when the developer transporting body and the photoconductor come into contact with each other, so that the impact is reduced. Can be relaxed.
[0031]
At this time, the cylindrical body of the nip forming member is formed as a separate component mounted on the developer conveying body having the same outer diameter as the developer conveying body, and the elastic layer of the nip forming member is It is desirable that the elastic layer supporting groove formed on the outer surface of the body in the circumferential direction is formed by injection molding.
[0032]
Also, the cylinder of the nip forming member is formed as a separate component mounted on the developer carrier having the same outer diameter as the developer carrier, and the elastic layer of the nip forming member is May be formed as a separate component which is sandwiched between elastic layer support grooves formed in the outer surface in the circumferential direction.
[0033]
Further, the cylindrical body of the nip forming member has the same outer diameter as the developer conveying body and is formed integrally with the developer conveying body, and the elastic layer of the nip forming member is formed on the outer surface of the cylindrical body. The elastic layer supporting groove formed in the circumferential direction may be formed by injection molding.
[0034]
Further, the cylindrical body of the nip forming member has the same outer diameter as the developer conveying body and is formed integrally with the developer conveying body, and the elastic layer of the nip forming member is provided outside the cylindrical body. It may be configured to be formed as a separate component sandwiched between elastic layer support grooves formed on the surface in the circumferential direction.
[0035]
At this time, the degree of shock absorption by the nip forming member and the thickness of the developing nip formed by the nip forming member may be adjusted by the thickness of the elastic layer protruding from the outer surface of the cylindrical body. it can.
[0036]
In addition, the degree of shock absorption by the nip forming member and the thickness of the developing nip formed by the nip forming member can be adjusted by the hardness of the elastic layer protruding from the outer surface of the cylindrical body.
[0037]
According to another aspect of the present invention, there is provided a first body in which an electrostatic latent image is formed, and a predetermined developing nip formed between the first body and the first body. A second body that contacts the body to develop the electrostatic latent image, and an impact that absorbs a contact shock applied from the second body to the first body to contact the first body with the second body. And a cushioning member.
[0038]
According to such a developing device according to the present invention, when the second body is brought into contact with the electrostatic latent image formed on the first body of the developing device to develop the electrostatic latent image, the shock absorbing member is used. Since the contact shock between the first body and the second body is absorbed and mitigated, deterioration of development quality due to the contact shock is prevented, image quality is stabilized, and damage to the photoreceptor due to the contact shock is prevented. Can be.
[0039]
At this time, the second body has one diameter, the shock absorbing member has one diameter, and the thickness of the developing nip is the difference between the diameter of the second body and the diameter of the shock absorbing member. When configured to be the same as the difference, the impact buffering member may be configured to contact the first body when the second body is brought into contact with the electrostatic latent image formed on the first body of the developing device for development. It can play a role of absorbing and mitigating a contact impact with the second body, and can also play a role of forming a developing nip between the first body and the second body.
[0040]
Further, the second body is a roller having one shaft, and the shock absorbing member is configured to include a cylinder disposed on the shaft, so that the cylinder of the shock absorbing member is connected to the second body. It becomes rotatable with the second body on the same axis.
[0041]
Further, the second body is a roller having one shaft, a plurality of shafts are further disposed at both ends of the roller, and the shock absorbing member is a plurality of cylinders disposed on each of the plurality of shafts. May be included. According to this structure, the plurality of cylindrical bodies of the shock absorbing member can rotate on the circumference around the shaft of the second body as the second body rotates. Therefore, the impact buffering member can play a role of absorbing a contact impact between the first body and the second body by the plurality of cylindrical bodies that rotate with the rotation of the second body. .
[0042]
Further, if the cylinder of the shock absorbing member is made of a non-conductive material, the developer on the surface of the first body can be removed when the cylinder of the shock absorbing member comes into contact with the first body. It can be prevented from adhering to the cylindrical body. Preferably, the cylinder of the shock absorbing member is formed of plastic.
[0043]
Further, if the shock absorbing member further includes a non-conductive elastic layer formed on an outer surface of the cylindrical body, the elastic layer absorbs a contact shock between the first body and the second body. Play a role. Further, since the elastic layer is made of a non-conductive material, it is possible to prevent the developer adhering to the surface of the first body from adhering due to static electricity.
[0044]
At this time, it is preferable that the diameter of the cylinder of the shock absorbing member is the same as the diameter of the second body. Also, the thickness of the developing nip can be adjusted by changing the thickness of the elastic layer of the shock absorbing member and / or the hardness of the elastic layer.
[0045]
According to another aspect of the present invention, a predetermined developing nip is formed between a first rotating body on which an electrostatic latent image is formed and the first rotating body. A second rotator that rotates together with the first rotator to develop the electrostatic latent image, a cylinder that rotates coaxially with the second rotator, and the cylinder that contacts the first rotator. A nip forming member provided with an elastic layer formed on an outer peripheral surface of the nip and determining a thickness of the developing nip according to at least one of its hardness and thickness. .
[0046]
According to the developing device of the present invention, the developing nip for developing the electrostatic latent image by bringing the second rotating body into contact with the electrostatic latent image formed on the first rotating body of the developing device. Is determined by at least one of the hardness and the thickness of the elastic layer of the nip forming member. Therefore, the thickness and the thickness of the developing nip are adjusted by adjusting the hardness and / or the thickness of the elastic layer. can do.
[0047]
According to another aspect of the present invention, a plurality of first bodies on which an electrostatic latent image is formed are provided corresponding to the plurality of first bodies, respectively. A plurality of second bodies each forming a predetermined developing nip between the first body and the first body, and contacting the first body to develop the electrostatic latent image with developers of different hues; A plurality of shock-absorbing members for absorbing a contact shock applied from the second body to the corresponding first body and bringing the first body and the second body into contact with each other. Is provided.
[0048]
According to such a developing device according to the present invention, the developing device includes the first body, the second body, and the shock buffering members, the number of which corresponds to the number of colors of the developer. Then, in a set of the first body, the second body, and the shock absorbing member provided correspondingly, the second body is brought into contact with the electrostatic latent image formed on the first body to form the electrostatic latent image. During development, the shock absorbing member absorbs and mitigates the contact shock between the first body and the second body, so that the deterioration of development quality due to the contact shock is prevented, the image quality is stabilized, and the impact due to the contact shock is prevented. Damage to the photoconductor can be prevented.
[0049]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of a nip forming device and a developing device of a developing device according to the present invention will be described in detail with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted.
[0050]
FIG. 2 shows a schematic configuration of the nip forming device 100 of the developing device according to the embodiment of the present invention. The nip forming device 100 of the developing device according to the present embodiment is provided in a color image forming device. The color image forming apparatus includes a photoconductor 111 and a developing device 131, a part of which is shown in FIG.
[0051]
The photoconductor 111 has a cylindrical drum shape, and an electrostatic latent image is formed on the surface of the photoconductor 111 by utilizing its potential characteristics. The developing device 131 serves as a developer transporter that forms a visible image by attaching a developer to the electrostatic latent image formed on the photoconductor 111 while rotating while being in contact with the photoconductor 111. The developing roller 113 is provided. The color image forming apparatus is provided with four such developing devices 131 (only one is shown), and prints a color image by a contact developing method.
[0052]
The photoreceptor 111 includes an aluminum pipe or cylinder 112 having a shaft 112c, and a photosensitive layer 112a coated on the outer surface of the cylinder 112 with a predetermined thickness except for the non-photosensitive layer portions 112b on both side edges. .
[0053]
The developing roller 113 of the developing device 131 has a shaft 113a, and is formed of a cylindrical tube or cylinder made of a metal such as an aluminum material or a conductive plastic material.
[0054]
The configuration of the developing device 131 other than the developing roller 113 is the same as the configuration of the developing devices 31, 32, 33, and 34 of the conventional color image forming apparatus 10 shown in FIG. Omit.
[0055]
The nip forming device 100 of the developing device according to the present embodiment is formed at both ends of the shaft 113a of the developing roller 113. The nip forming apparatus 100 alleviates the contact impact when the developing roller 113 moves toward the photoconductor 111 and comes into contact with the photoconductor 111 in order to develop the corresponding color. At the same time, the nip forming device 100 of the developing device stably forms the developing nip of a predetermined thickness between the developing roller 113 and the photoconductor 111 so that the developing roller 113 and the photoconductor 111 rotate. Maintained development quality.
[0056]
The nip forming devices 100 are provided at both ends of the developing roller 113, and have outer diameters whose outer diameters protrude from the circumferential surface of the developing roller 113 by a predetermined thickness of the developing nip described above. 100b. The nip forming members 100a and 100b form a developing nip having a predetermined thickness between the developing roller 113 and the photoconductor 111, and at the same time, cushion the impact when the developing roller 113 comes into contact with the photoconductor 111. Also serves as a member.
[0057]
FIG. 3 is a diagram illustrating a configuration of the nip forming member 100a of the nip forming device 110 of the developing device according to the present embodiment. The right half of FIG. 3 is a plan view of the nip forming member 100a, and the left half is a cross-sectional view. FIG. 4 is a cross-sectional view taken along line II of the nip forming member 100a of FIG. 3, that is, a vertical cross-sectional view.
[0058]
The nip forming members 100a and 100b are two small rollers which are disposed one at each end of the shaft 113a of the developing roller 113 and include a cylindrical body 110 and an elastic layer 120. The cylindrical body 110 is made of a non-conductive plastic material such as polycarbonate (PC) or polyacetal (POM). The elastic layer 120 is formed on the outer surface of the cylindrical body 110 and is made of a material such as non-conductive rubber.
[0059]
Both cylindrical bodies 110 of the nip forming members 100a and 100b have the same outer diameter as the developing roller 113, and are forcibly fitted to the shaft 113a of the developing roller 113.
[0060]
An elastic layer support groove 130 is formed on the outer surface 116 of the cylindrical body 110 so that the elastic layer 120 can be formed in the circumferential direction. The elastic layer 120 is desirably formed in the elastic layer support groove 130 by injection molding. Alternatively, after forming the elastic layer 120 as a separate component, the elastic layer 120 can be sandwiched between the elastic layer support grooves 130 of the cylindrical body 110.
[0061]
The cylindrical body 110 may be formed integrally with the developing roller 113 or the shaft 113a of the developing roller 113. In this case, as in the case where the cylindrical body 110 is formed as a separate component from the developing roller 113, the outer diameter of the cylindrical body (not shown) is the same as that of the developing roller 113, and An elastic layer support groove (not shown) for forming an elastic layer (not shown) is formed on the outer surface. Similarly, the elastic layer is formed by injection molding in the elastic layer support groove, or is formed as a separate component and is sandwiched in the elastic layer support groove.
[0062]
The portion of the elastic layer 120 formed in the elastic layer support groove 130 protruding from the outer surface 116 of the cylindrical body 110, that is, the protruding portion having the thickness t, is moved by the roller 113 in the direction of the photoconductor 111. A development nip is formed which reduces contact impact when contacting the photoconductor 111 and maintains uniform and stable development quality. The effect is the same whether the elastic layer 120 is formed by injection molding or as a separate part.
[0063]
At this time, by adjusting the thickness t of the protruding portion, the developing nip can be adjusted so as to have an optimum value at which the developing quality is the best. Similarly, by adjusting the thickness t of the protruding portion, it is possible to adjust the degree of buffering of the contact impact when the photoconductor 111 and the developing roller 113 come into contact. As described above, the thickness of the developing nip and the degree of shock absorption can be adjusted by the thickness of the elastic layer 120, but can also be adjusted by the hardness of the elastic layer 120.
[0064]
In addition, since the elastic layer 120 and / or the cylindrical body 110 is in contact with the photosensitive layer 112a of the photosensitive body 111, there is a possibility that the developer adheres due to static electricity. can do. Therefore, it is possible to prevent image quality deterioration phenomena such as image defects from occurring due to contamination of the nip forming apparatus 100.
[0065]
As described above, in the nip forming apparatus 100 of the developing device according to the present embodiment, the elastic layer 120 reduces the contact impact when the developing roller 113 comes into contact with the photoconductor 111 while keeping the developing roller 113 in contact with the photoconductor 111 at a constant pressure. By doing so, it is possible to maintain the development nip of a predetermined thickness t to improve the image quality, and to prevent the image quality from deteriorating due to contact impact and the damage of the photosensitive layer 112a of the photoconductor 111. At this time, if both the photoconductor 111 and the developing roller 113, particularly the photoconductor 111, are made of a hard material such as plastic or metal, the nip forming apparatus 100 of the developing device can exhibit more excellent effects.
[0066]
Next, the developing device according to the present embodiment including the nip forming device of the developing device having such a configuration will be described. The developing device 131 including the nip forming device 100 includes, in addition to the developing roller 113, the developer accommodating portion 16, the developer supply roller 15, and the developer regulating member 51, similarly to the conventional developing device 13 shown in FIG. Prepare.
[0067]
As in the prior art, an electrostatic latent image is formed on the photoconductor 111, and the developing device 131 of the corresponding color moves in the direction of the photoconductor 111 to develop the electrostatic latent image. Set to position. Then, the developing roller 113, the developer supply roller 15, and the developer regulating member 51 are respectively driven to rotate by a developing device drive source, and the developer in the developer accommodating section 16 is supplied to the developing roller 113 via the developer supply roller 15. Supplied to The thickness of the developer supplied to the developing roller 113 is regulated by the developer regulating member 51, and a thin layer of the developer is formed on the developing roller 113.
[0068]
When the developing roller 113 is brought into contact with the photoconductor 111 to perform the development, the developing device 131 according to the present embodiment absorbs the contact impact by the nip forming device 100 of the developing device. An appropriate developing nip is formed between the developing roller 113 and the developing roller 113.
[0069]
The image forming process of the image forming apparatus including the developing device according to the present embodiment configured as described above is the same as that of the related art, and the description thereof is omitted.
[0070]
As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but it is needless to say that the present invention is not limited to the examples. It is clear that a person skilled in the art can conceive various changes or modifications within the scope of the claims, and these naturally belong to the technical scope of the present invention. I understand.
[0071]
For example, although the nip forming device 100 of the developing device according to the present embodiment is provided at both ends of the shaft 113a of the developing roller 113, the nip forming device 100 may be provided at both ends of the photoconductor 111 with the same configuration. it can.
[0072]
Also, the nip forming members 100a and 100b of the nip forming device 100 of the developing device according to the present embodiment are cylindrical bodies that are disposed one by one on both ends of the developing roller 113 coaxially with the shaft 113a of the developing roller. Instead of providing one cylindrical body at the end of the developing roller 113, a plurality of shafts are further provided at the end of the developing roller 113, and a plurality of cylindrical bodies are arranged on each of the plurality of shafts. , A nip forming device of a developing device. With such a configuration, the plurality of cylindrical bodies can be rotationally moved on a circumference centered on the shaft 113a of the developing roller with the rotation of the developing roller 113. Therefore, the nip forming device of the developing device can absorb the contact impact between the photoconductor 111 and the developing roller 113 by the plurality of cylindrical bodies that rotate with the rotation of the developing roller 113.
[0073]
Further, the nip forming members 100a and 100b of the nip forming device 100 of the developing device according to the present embodiment also serve as an impact buffering member for reducing the impact when the developing roller 113 comes into contact with the photoconductor 111. It may be provided separately from the nip forming member.
[0074]
In addition, the developing device including the nip forming device of the developing device according to the present embodiment has a configuration in which different color images are superposed and developed on the surface of the single photoconductor 111 described above, instead of the developer. A plurality of photoconductors corresponding to the number of colors may be provided, and each photoconductor may be configured to develop a single color image.
[0075]
【The invention's effect】
As described in detail above, according to the present invention, when the developer carrier comes into contact with the photoreceptor to perform development, the nip forming member having an elastic layer serving as a cushioning material is provided, so that the developer carrier is provided. An object of the present invention is to provide a nip forming device and a developing device of a developing device capable of mitigating a contact impact when contacting a photoreceptor and preventing deterioration of image quality and damage of a photosensitive layer of the photoreceptor due to the contact impact. . At this time, if both the photosensitive member and the developer conveying member, particularly, the photosensitive member are made of a hard material such as plastic or metal, a more excellent contact shock buffering effect can be obtained.
[0076]
Further, according to the present invention, by providing the nip forming member, the contact impact between the developer transport body and the photoconductor is reduced, and at the same time, the developer transport body and the photoconductor are brought into contact with each other at a predetermined pressure to thereby prevent the predetermined pressure. Accordingly, it is possible to provide a nip forming device and a developing device of a developing device in which a developing nip having a thickness of is formed to maintain good image quality.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a schematic configuration of a conventional color image forming apparatus.
FIG. 2 is a plan view showing a schematic configuration of a nip forming device of the developing device according to the embodiment of the present invention.
FIG. 3 is a diagram showing a configuration of a nip forming member of the nip forming device of the developing device according to the embodiment.
FIG. 4 is a sectional view taken along line II of FIG. 3;
[Explanation of symbols]
10 Image forming apparatus
11 Photoconductor
12 First charger
13 Developing roller
15 Developer supply roller
16 developer container
20 Laser Scanning Unit
31, 32, 33, 34 developing device
35, 36, 37, 38 cam
51 Developer regulating member
56 rotation axis
60 Transfer and transport unit
74 Release spring
87 Static elimination lamp
80 Cleaning static eliminator
111 photoconductor
112a photosensitive layer
113 Development roller
113a shaft
131 Developing device
100a, 100b Nip forming member
110 cylindrical body
120 elastic layer
130 elastic layer support groove

Claims (20)

静電潜像が形成される感光体と，前記感光体に接触して前記静電潜像に現像剤を付着させて可視画像を形成する少なくとも一つ以上の現像剤搬送体とを備える電子写真方式画像形成装置の現像装置のニップ形成装置であって，
前記現像剤搬送体または前記感光体のいずれか一方の両端に，前記感光体と前記現像剤搬送体との間に位置するように配設されるニップ形成部材を含み，
前記各ニップ形成部材の円周面の少なくとも一部は，前記ニップ形成部材が配置される前記現像剤搬送体または前記感光体の円周面よりも，前記現像剤搬送体と前記感光体とが接触したときに所定の現像ニップが形成される程突出されて形成されること，
を特徴とする現像装置のニップ形成装置。Electrophotography comprising a photoreceptor on which an electrostatic latent image is formed, and at least one or more developer transporters for contacting the photoreceptor and adhering a developer to the electrostatic latent image to form a visible image Nip forming device of the developing device of the image forming apparatus,
A nip forming member disposed at both ends of either the developer carrier or the photoconductor so as to be located between the photoconductor and the developer carrier;
At least a portion of the circumferential surface of each of the nip forming members has a greater distance between the developer conveying body and the photosensitive member than the circumferential surface of the developer conveying body or the photosensitive member on which the nip forming member is disposed. Projecting so as to form a predetermined developing nip when contacted,
A nip forming device for a developing device. 前記ニップ形成部材は，
円筒体及び前記円筒体の外部表面に形成された非導電性の弾性層を有する，前記現像剤搬送体の両端に一つずつ設置される二つの小ローラにより構成されることを特徴とする請求項１に記載の現像装置のニップ形成装置。The nip forming member is
The image forming apparatus according to claim 1, further comprising: two small rollers having a cylindrical body and a non-conductive elastic layer formed on an outer surface of the cylindrical body, each of which is provided at both ends of the developer conveying body. Item 2. A nip forming device for a developing device according to Item 1. 前記ニップ形成部材の円筒体は，前記現像剤搬送体と同一外径を有する前記現像剤搬送体に装着される別個の部品として形成され，
前記ニップ形成部材の弾性層は，前記円筒体の外部表面に円周方向に形成された弾性層支持溝に射出成形により形成されることを特徴とする請求項２に記載の現像装置のニップ形成装置。The cylindrical body of the nip forming member is formed as a separate component mounted on the developer carrier having the same outer diameter as the developer carrier.
3. The nip forming device according to claim 2, wherein the elastic layer of the nip forming member is formed by injection molding in an elastic layer supporting groove formed in a circumferential direction on an outer surface of the cylindrical body. apparatus. 前記ニップ形成部材の円筒体は，前記現像剤搬送体と同一外径を有する前記現像剤搬送体に装着される別個の部品として形成され，
前記ニップ形成部材の弾性層は，前記円筒体の外部表面に円周方向に形成された弾性層支持溝に挟込まれる別個の部品として形成されることを特徴とする請求項２に記載の現像装置のニップ形成装置。The cylindrical body of the nip forming member is formed as a separate component mounted on the developer carrier having the same outer diameter as the developer carrier.
3. The developing device according to claim 2, wherein the elastic layer of the nip forming member is formed as a separate component which is sandwiched between elastic layer supporting grooves formed in a circumferential direction on an outer surface of the cylindrical body. Device nip forming device. 前記ニップ形成部材の円筒体は，前記現像剤搬送体と同一外径を有して前記現像剤搬送体と一体に形成され，
前記ニップ形成部材の弾性層は，前記円筒体の外部表面に円周方向に形成された弾性層支持溝に射出成形により形成されることを特徴とする請求項２に記載の現像装置のニップ形成装置。The cylindrical body of the nip forming member has the same outer diameter as the developer carrier, and is formed integrally with the developer carrier.
3. The nip forming device according to claim 2, wherein the elastic layer of the nip forming member is formed by injection molding in an elastic layer supporting groove formed in a circumferential direction on an outer surface of the cylindrical body. apparatus. 前記ニップ形成部材の円筒体は，前記現像剤搬送体と同一外径を有して前記現像剤搬送体と一体に形成され，
前記ニップ形成部材の弾性層は，前記円筒体の外部表面に円周方向に形成された弾性層支持溝に挟込まれる別個の部品として形成されることを特徴とする請求項２に記載の現像装置のニップ形成装置。The cylindrical body of the nip forming member has the same outer diameter as the developer carrier, and is formed integrally with the developer carrier.
3. The developing device according to claim 2, wherein the elastic layer of the nip forming member is formed as a separate component which is sandwiched between elastic layer supporting grooves formed in a circumferential direction on an outer surface of the cylindrical body. Device nip forming device. 前記ニップ形成部材による衝撃緩衝の度合い，及び前記ニップ形成部材により形成される現像ニップの厚さは，前記円筒体の外部表面から突出された前記弾性層の厚さによって調節されることを特徴とする請求項２に記載の現像装置のニップ形成装置。The degree of shock absorption by the nip forming member and the thickness of the developing nip formed by the nip forming member are adjusted by the thickness of the elastic layer protruding from the outer surface of the cylindrical body. The nip forming device for a developing device according to claim 2. 前記ニップ形成部材による衝撃緩衝の度合い，及び前記ニップ形成部材により形成される現像ニップの厚さは，前記円筒体の外部表面から突出された前記弾性層の硬度によって調節されることを特徴とする請求項２に記載の現像装置のニップ形成装置。The degree of shock absorption by the nip forming member and the thickness of the developing nip formed by the nip forming member are adjusted by the hardness of the elastic layer protruding from the outer surface of the cylindrical body. A nip forming device for a developing device according to claim 2. 静電潜像が形成される第１胴体と，
前記第１胴体との間に所定の現像ニップを形成して前記第１胴体と接触して前記静電潜像を現像する第２胴体と，
前記第２胴体から前記第１胴体へ加えられる接触衝撃を吸収して前記第１胴体と前記第２胴体とを接触させる衝撃緩衝部材とを含むこと，
を特徴とする現像装置。A first body on which an electrostatic latent image is formed;
A second body for forming a predetermined developing nip between the first body and the first body to contact the first body to develop the electrostatic latent image;
An impact buffering member that absorbs a contact impact applied from the second body to the first body and contacts the first body and the second body;
A developing device characterized by the above-mentioned. 前記第２胴体は一つの直径を有し，前記衝撃緩衝部材は一つの直径を有し，前記現像ニップの厚さは，前記第２胴体の直径と前記衝撃緩衝部材の直径との差と同一であることを特徴とする請求項９に記載の現像装置。The second body has one diameter, the shock absorbing member has one diameter, and the thickness of the developing nip is the same as the difference between the diameter of the second body and the diameter of the shock absorbing member. The developing device according to claim 9, wherein: 前記第２胴体は一つのシャフトを有するローラであり，前記衝撃緩衝部材は前記シャフト上に配置された円筒体を含むことを特徴とする請求項９及び１０に記載の現像装置。The developing device according to claim 9, wherein the second body is a roller having one shaft, and the shock absorbing member includes a cylinder disposed on the shaft. 前記第２胴体は一つのシャフトを有するローラであり，前記ローラの両端部には更に複数のシャフトが配置され，前記衝撃緩衝部材は前記複数のシャフトのそれぞれに配置された複数の円筒体を含むことを特徴とする請求項９に記載の現像装置。The second body is a roller having a single shaft, a plurality of shafts are further disposed at both ends of the roller, and the shock absorbing member includes a plurality of cylinders disposed on each of the plurality of shafts. The developing device according to claim 9, wherein: 前記衝撃緩衝部材の円筒体は，非導電性の材質から成ることを特徴とする請求項１１に記載の現像装置。The developing device according to claim 11, wherein the cylinder of the shock absorbing member is made of a non-conductive material. 前記衝撃緩衝部材の円筒体は，プラスチックで形成されることを特徴とする請求項１１に記載の現像装置。The developing device according to claim 11, wherein the cylinder of the shock absorbing member is formed of plastic. 前記衝撃緩衝部材は，前記円筒体の外部表面に形成された非導電性の弾性層をさらに含むことを特徴とする請求項１１に記載の現像装置。The developing device of claim 11, wherein the shock absorbing member further includes a non-conductive elastic layer formed on an outer surface of the cylindrical body. 前記衝撃緩衝部材の円筒体の直径は，前記第２胴体の直径と同一であることを特徴とする請求項１１に記載の現像装置。The developing device according to claim 11, wherein the diameter of the cylinder of the shock absorbing member is the same as the diameter of the second body. 前記現像ニップの厚さは，前記衝撃緩衝部材の弾性層の厚さにより調節されることを特徴とする請求項１５に記載の現像装置。The developing device according to claim 15, wherein a thickness of the developing nip is adjusted by a thickness of an elastic layer of the shock absorbing member. 前記現像ニップの厚さは，前記衝撃緩衝部材の弾性層の硬度により調節されることを特徴とする請求項１５に記載の現像装置。16. The developing device according to claim 15, wherein a thickness of the developing nip is adjusted by a hardness of an elastic layer of the shock absorbing member. 静電潜像が形成される第１回転体と，
前記第１回転体との間に所定の現像ニップを形成して前記第１回転体と共に回転して前記静電潜像を現像する第２回転体と，
前記第２回転体と同軸上で共に回転する円筒体，及び前記第１回転体と接触するよう前記円筒体の外周面に形成されてその硬度と厚さのうち少なくとも一つによって前記現像ニップの厚さを決定する弾性層を備える，ニップ形成部材とを含むこと，
を特徴とする現像装置。A first rotating body on which an electrostatic latent image is formed;
A second rotating body that forms a predetermined developing nip with the first rotating body and rotates together with the first rotating body to develop the electrostatic latent image;
A cylindrical body that rotates coaxially with the second rotating body, and an outer peripheral surface of the cylindrical body that is in contact with the first rotating body, and that has at least one of hardness and thickness of the developing nip. A nip forming member having an elastic layer for determining the thickness;
A developing device characterized by the above-mentioned. 静電潜像が形成される複数の第１胴体と，
前記複数の第１胴体とそれぞれ対応して設けられ，対応する前記第１胴体との間に所定の現像ニップを形成して前記第１胴体とそれぞれ接触して，それぞれ異る色相の現像剤で前記静電潜像を現像する複数の第２胴体と，
前記それぞれの第２胴体から前記対応する第１胴体へ加えられる接触衝撃を吸収して前記それぞれの第１胴体と第２胴体とを接触させる複数の衝撃緩衝部材とを含むこと，
を特徴とする現像装置。A plurality of first bodies on which an electrostatic latent image is formed;
A plurality of first bodies are provided corresponding to the plurality of first bodies, respectively, a predetermined developing nip is formed between the plurality of first bodies and the first bodies are brought into contact with the first bodies. A plurality of second bodies for developing the electrostatic latent image;
A plurality of shock-absorbing members for absorbing contact impact applied from the respective second bodies to the corresponding first bodies and bringing the respective first and second bodies into contact with each other;
A developing device characterized by the above-mentioned.
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